NECTARY. 49 
4. Caryophyllaceous, like the pink. This corolla consists of 
five petals, having long claws immersed in a tubular calyx. Ex. 
pink, cockle (Fig. 4). 
5. Papilionaceous, butterfly-shaped. This corolla consists of 
five dissimilar petals, which have received names as follows ; — 
the upper and largest is called the banner (vexillum); the two 
lateral ones beneath this, the wings (ale); and the two lower 
ones cohering by their lower margins, the keel (carina). Exam- 
ples, pea, bean, locust. Plants with this kind of corolla consti- 
tute the greater part of the Leguminose, one of the most 
extensive and useful of the natural families. 
106, PuysioLocicaL structure. ‘The floral envelopes are 
found, in their physical organization, to agree with leaves, of 
which they are only modifications. They consist of thin expan- 
sions of cellular tissue, traversed by veins of delicate spiral 
vessels, all covered with an epidermis often having stomata. 
Their various colors are produced by secretions contained in the 
little bladders of the cellular tissue. 
$7. OF THE NECTARY AND DISK. 
107. These are terms which have been applied to certain 
anomalous forms of the floral organs, and are very variable in 
structure and position. 
a. The NecTARY (nectar, honey) is properly an apparatus for the secretion of | 
honey. In the violet, larkspur, columbine, &c., it consists of a prolongation of 
the petal into a spur. In the nasturtium it is a similar prolongation of the sepal. 
In the passion flower, grass parnassus, gold-thread, &c., the nectaries are merely 
abortive stamens passing into petals. In the lady’s slipper and other Orchida- 
ceous plants, the lower petal being inflated and larger than the rest of them, was 
called nectary by the Linnean school, but by modern writers the labellum, or 
lip. 
b. The p1sxK is 4 term applied to certain little projections situated between the 
bases of the stamens and the pistils. Its more common form is that of a raised 
_ rim, either entire or variously lobed, surrounding the base of the ovary, that is, 
hypogynous (i=, under, zvvu, the pistil), as in the peony, or it appears at the top 
of the ovary when the calyx is superior, and is then said to be epigynous (em, 
upon, 71), as in the Cornus. 
c. The true character of the disk is little understood. It is supposed by 
Lindley to consist of stamens in a rudimentary state, as it is sometimes separated 
into a circle of glandular bodies, alternating with the true stamens. 
va 
